Few-body correlations in nuclear systems

轻元素(2H、~3H、~3He、~4He)被嵌入到核介质中后，其性质发生了改变。在准粒子方法中，团簇的能量依赖于质心动量以及密度、温度和周围介质的不对称性。目前，这些准粒子的能量移动是在不相关介质的假设下计算的。我们以一种自洽的方式考虑了介质(即组成)中的相关性来计算位移。准确计算介质中的少核子关联是评价核物质组成和状态方程的一个重要因素。它可以用在天体物理学中来描述致密物体(超新星、中子星)，也可以用来研究重离子碰撞。少数核子关联，特别是α聚集，在核结构物理中是很有意义的。我们研究了重核表面附近的类阿尔法关联(四重态)。特别是，对于重核的α衰变，例如钚同位素的阿尔法衰变，计算了阿尔法预构因数。

The properties of light elements (2H, 3H, 3He, 4He) are modified when they are imbedded in a nuclear medium. Within a quasiparticle approach, the energies of the clusters are dependent on the center of mass momentum as well as the density, the temperature, and the asymmetry of the surrounding medium. At present, these quasiparticle energy shifts are calculated assuming an uncorrelated medium. We calculate the shifts taking into account correlations in the medium (i.e. the composition) in a self-consistent way. A precise calculation of in-medium few-nucleon correlations is an important ingredient for the evaluation of the composition and the equations of state of nuclear matter. It can be applied in astrophysics to describe compact objects (supernovae, neutron stars) as well as in the investigation of heavy-ion collisions. Few-nucleon correlations, in particular alpha clustering, is of interest in nuclear structure physics. We investigate alpha-like correlations (quartets) near the surface of heavy nuclei. In particular, the alpha preformation factor is calculated for the alpha-decay of heavy nuclei, e.g., of the polonium isotopes.